Infrastructure services company FM Conway is claiming a new benchmark for recycling in the highways industry with a landmark project on the A40 with Transport for London (TfL).
FM Conway has laid an asphalt surface course containing 50% high polished surface value recycled aggregate, which it said marks a pivotal shift in the way that roads are built and maintained in the UK. The project resurfaced over 20,000 metres on the road in west London,
It said this is the first time that a surface course mix containing such a high proportion of recycled material has been laid on a strategic route outside of trial conditions. The project follows a successful trial carried out by FM Conway and TfL last year to lay a high-recycled asphalt mix on the A1.
Tim Metcalf, aggregates and asphalt director at FM Conway, said: ‘Our trial with TfL last year proved that high-recycled surface course materials are both able to perform and environmentally sustainable. The project on the A40 takes this work to the next level, using insights from the trial to make recycling standard practice on the strategic network.’
TfL’s highways technical manager, Herbert Micallef, said: ‘Asphalt recycling does happen but so far the highways sector has been slow to accept it as best practice for work on both the strategic and local networks. FM Conway and TfL are changing this, bringing benefits for both road users and network operators.
‘Aggregate and bitumen are finite resources. We need to look to more sustainable alternatives if we’re going to continue providing a high-quality surface network for London’s road users now and in the future. Increasing the uptake of recycling and investing in advanced materials is a smarter, cost-effective way of doing this, helping us to unlock historic investment in London’s roads by recovering asphalt for reuse.’
FM Conway said standard practice has been to limit the recycled content of surface courses for motorways and A-roads to around 10%.
The material incorporates FM Conway’s own designed and manufactured Polymer Modified Bitumen (PMB). The addition of PMB to an asphalt mix can significantly improve the durability of highways assets by improving their resistance to rutting and cracking.
The firm added that the A40 works also saw an innovative laying technique to speed up delivery and cut costs. In contrast to traditional methods, which see surfacing materials laid in two layers at a depth of 100mm, the new material was laid in one go at a depth of 70mm, speeding up the resurfacing process.